Electrical Properties of a-IGZO Thin Film Transistors with Tetraethylorthosilicate (TEOS) Based SiO_2 Gate Insulator Layer

摘要

We investigated the influence of TEOS based SiO_2 gate insulator layer on the characteristics of a-IGZO thin film transistors (TFTs). The device characteristics were found to be sensitive to deposition conditions of gate insulator layer such as gas flow rate, temperature, and pressure. We have reduced threshold voltage shift of a-IGZO TFTs under positive bias temperature stress of V_g - 30V at 60°C for 3000 sec to 0.21V by optimizing TEOS based SiO_2 gate insulator layer deposition conditions.